The present invention broadly relates to infeeding and outfeeding of substantially flat articles or products from an imbricated formation and, more specifically pertains to a new and improved method of outfeeding printed products, particularly multi-sheet and preferably folded printed products, which are infed in an imbricated formation, arranged in tandem or succession and located at a predetermined spacing or pitch from one another, and imbricatingly overlap one another. Moreover, in each case at least two printed products are collectively engaged in the region of their leading edges by grippers or gripper elements of an outfeed device. The present invention also relates to a new and improved apparatus for outfeeding such printed products.
Such an apparatus is known, for example, from Swiss Patent No. 630,583 and its cognate U.S. Pat. No. 4,320,894, granted Mar. 23, 1982 and the British Patent No. 2,024,176, published Jan. 9, 1980. An infeed device or infeed conveyor of this known apparatus transports the printed products in an imbricated formation, during which each printed product bears upon the next following or trailing printed product, to a take-over region.
An outfeed device or outfeed conveyor comprises individually controllable grippers arranged in tandem or succession at a revolvingly driven traction element and at a mutual spacing or distance from one another. The conveying direction of the outfeed device in the take-over region extends essentially transversely with respect to the plane of the printed products to be engaged and furthermore from the underside of the printed products towards the upper side of such printed products. In this known apparatus, each gripper in each case engages in the take-over region one infed printed product and peels off or removes this one engaged infed printed product from the imbricated formation. By appropriately reducing the conveying speed of the outfeed device in relation to the conveying speed of the infeed device and by reducing the imbricated spacing or pitch of the arriving imbricated product stream, it is however also possible to engage and outfeed, by means of a single gripper, two or more printed products. Owing to the reduction of the conveying speed of the outfeed device, the leading edge of the foremost printed product of the infed imbricated formation travels against a stop element or rail such that the imbricated spacing or pitch is reduced and the next following printed product travels further under the preceding or downstream printed product until these two printed products are mutually outfed.
The reduced imbricated spacing or pitch between the two printed products engaged in each case by one or a single gripper is particularly suitable for further processing of printed products in a device as known from and disclosed in European patent application No. 0,237,701 and its cognate U.S. Pat. No. 4,709,910, granted Dec. 1, 1987. In this known apparatus, the free ends of the two printed products held by a gripper or gripper element are separated from one another by means of the reduced imbricated spacing or pitch and introduced, in each case, into different pockets or compartments of a revolving drum.
On the other hand, if for further processing of the printed products there is again required an imbricated formation in which the printed products are arranged having their original spacing or pitch, then following the known outfeeding apparatus there must be arranged a further apparatus which again increases the reduced spacing or pitch between the two printed products engaged or seized by one individual gripper. This entails considerable additional structural resources.